This removes the %http-response special case from gall. In its place,
we implement a subscription regime with the following steps:
- Agent sends %connect to Eyre
- Eyre pokes agent with %handle-http-response, including unique eyre-id
- Agent passes %start-watching to Eyre with eyre-id and unique app-id
- Eyre subscribes to agent on /http-response/app-id
- Agent produces a %http-response-header fact followed by 0 or more
%http-response-data facts and possibly a %http-response-cancel fact
- Agent produces a %kick to close the subscription, which Eyre
interprets as completion of the message.
This works when there is data. There is currently a bug where if the
response has no data in total (as in the case of a naked 404), no
response will be sent.
This also includes lib/http-handler, which implements a convenient
interface for agents that want to respond immediately with all the data.
This lets them avoid carrying extra state to keep track of pending
requests.
This should really have access to your state and the ability to change
it. Perhaps a more minimalist design would be better: just keep track
of the requests, then hand it off to +on-watch when eyre is ready to
receive responses. It's not clear how to pass in the request data in
+on-watch.
